Since my post about pyrolyzing biomass stoves, I’ve been trying to understand how the Lucia Stove works. A lot of the pyrolyzing stoves are “TLUDs” (Top Lit Updraft). My understanding was that TLUDs really only work well in batch mode, while the Lucia Stove promises that more fuel can be added during a burn run. Unfortunately the WorldStove site and YouTube Videos contain just enough information to confuse me, so I went digging around the Stoves Mailing list and finally found what I was looking for, in an explanation by Nat Mulcahy to some questions posed by Clement Davis.
Category Archives: General
Biofuel Stoves
A friend of a friend on Facebook posted photos of a compact wood cooking stove he made which pyrolizes wood or other dry biomass, and it sent me reading. I though I’d try to document some of what I learned and note some of the more interesting links.
Pyrolization is the process of thermally decomposing hydrocarbons in an oxygen poor or oxygen free environment. The products are char, ash, various gases, liquids and tars. Charcoal is made by pyrolization by heating wood in a low oxygen environment. Often, the heat is provided by partial combustion of the wood. The partial combustion drives much of the fuel content is driven off as smoke, and leaves behind charcoal. Pyrolizing wood stoves harness the energy content in the smoke by adding hot air to it and burning it thoroughly. The heat is used for cooking or heating. The resulting charcoal can be burned for other uses, or composted to improve soil quality and provide a way to sequester carbon long-term to help fight global warming.
My own interest in pyrolyzing wood stoves is motivated by a few things. I like tinkering and highly constrained engineering problems, I’m interested in renewable energy and sustainability, and I’m concerned about how I’m going to eat and stay warm if the US and global economies collapse because of declining oil production. Also, I like fire.
I don’t seem entirely alone in my motivations for being interested in stoves. Stoves in genreal have received a lot of attention over the last decade or more. People have looked for ways to improve efficiency and improve flexibility of fueling while working within tight cost-constraints and limited available materials and tools. Improved efficiency reduces fuel consumption. It also reduces pollution, both due to reduced fuel consumption to cook a given amount of food, and more thorough combustion, which produces less smoke from a given amount of fuel. Reduced fuel consumption frees money and/or time that would otherwise be spent on procuring fuel. It also reduces the environmental toll of collecting fuel. Stoves which can adapt to different sources of fuel, or adapting efficient stove designs to local fuel sources also helps reduce the environmental toll. Some stoves let people cook with dried dung, or grass, rather than having to use already scarce wood, or let people cook with waste, like rice chaff or waste paper, rather than having to make special efforts to get cooking fuel.
Balancing these objectives against local conditions has lead to a wide variety of stove designs. Many seem driven solely by efficiency and low cost. Whether or not pyrolyzing wood stoves really hit the sweet spot there depends on your point of view. They can certainly be quite inexpensive; You can build one suitable for a single-family cookpot out of a couple of coffee cans, some tin-snips, and something you can punch holes in the sheet metal with. Whether or not they are efficient depends on what you are comparing them too. If you are comparing them to a good stove that completely consumes all the wood fed into it, then the charcoal from a pyrolyzing stove represents energy that could have gone into cooking. If you step back and consider that the charcoal produced by the stove will offset charcoal that might have been produced in a manner that just dumped the tars and volatile gases from the wood into the air as smoke, then the pyrolizing stove looks a good bit better. As I mentioned earlier though, the ability of “biochar” to serve as a soil amendment and carbon sink has boosted the interest in pyrolysing stoves.
There is a huge amount of information out there about all manner of biomass burning stoves, and I’m still trying to get my head around it, but in the meantime, I thought I’d share some of the more interesting sources I’ve found:
- BioenergyLists.org is a clearinghouse of information from a variety of sources and authors. They cover fuels, a variety of different types of stoves and cookers, important design approaches and other considerations, like construction techniques and materials, measurements of performance and emissons. They also host mailing lists with active discussions of these and other stove-related topics.
- StoveTec sells very efficient “rocket”-style stoves for $35-40 in the US made from a combination of metal and light-weight ceramic. They also sell their stoves outside the US for $3-12 per unit when purchased a shipping container at a time.
- The Aprovecho Research Center is connected to StoveTec. They’ve been working on designing and implementing improved biomass cooking and heating technologies for almost 30 years.
- WorldStove also produces stoves for developing countries, as well as models intended for customers in developed countries. They differ a bit from many others in that some of the parts use advanced manfacturing techniques to produce an air-inlet that creates a vortex, leading to more efficient combustion.
- Their “Beaner Stove” is a small stove designed for backpackers that uses a softdrink can as an outer-sleeve and can burn everything from pineneedles to vodka.
- They also have plans for the DIY EverythingNice stove, which can be made from a couple peices of sheet metal, or a few metal cans.
- GoodStove.com is a gateway to a number of different stove designs created by Dr. N. Sai Bhaskar Reddy.
- Lanny Hanson has some nice, concise YouTube videos demonstrating the efficacy of some of his stove designs.
Most of these designs are “open source,” in the hope that people will make improvements and share what they learn.
I really need to do more research. The more I read the less I think I understand. I’ll try to update this post or write new posts as I learn more.
ARM vs Intel-lovers
Fascinating to see how myopic people are. I was going through the forums on Ars Technica and came across a thread titled “why are upcoming ARM netbooks hyped so much? Noone wants ARM.” The thread kicked off with this:
This is getting really silly. Why does the IT media seem so obsessed with hyping upcoming ARM-based notebooks? You’d think that the netbook manufacturers actually learned and took a few hints from their first few releases, most notabling that: the market at large wants to run full blown Windows on their notebooks. Linux is a niche and a small one at that. ARM CPUs can run Linux / WinCE / Android, neither of these 3 are “full blown Windows”, therefor ARM based netbooks are doomed to fail by default.
There were arguments both ways, but I was struck, again, by how invested some people get in defending their captors. I ended up posting the following as a comment.
Noone” wants ARM? How about this, I know a bunch of people who don’t care if their netbook has Intel or Windows inside, because everything they use if for happens in a web browser. Cheap, compact, and long battery life? That’s something they actually want.
And don’t forget all the people in developing markets who either do no computing at all, or they are already ARM users because their primary access to computing is through a mobile phone. An ARM netbook would be a nice step up. Not that they have any particular affection for ARM, unless, of course, its made by a local ARM licensee.
As for all you “IT” guys who feel your pants tighten when you think about upgrading your ESXi cluster to some new Nehalems, there are guys who are responsible for more virtual machine instance hours in a day than you will be in your whole lifetime, swapping fantasies with guys who’se applications won’t run on the biggest, baddest Nehalem box, much less a long aisle of racks stuffed full of Sandybridges. Those guys, they are fantasizing about how much power and money they can save with assloads of systems build on upcoming high-volume, low-cost ARM SoCs. Those guys are going to put nine out of ten of you Windows-cleaners out of work if you cling to the old-way of doing things for too long.
And “chipguy,” don’t forget, Intel got its start in the microprocessor business supplying chips for desktop calculators. Read some Clayton Christensen. Modest beginnings have led to big things, and toppled old empires in the tech business again and again. No reason to think it won’t happen again.
Intel has to invest a lot of capital to hold on to its lead. I don’t know about you, but in the long run, I’d bet on a competitive ecosystem over a command-economy for the efficient allocation of capital.
Dog Park
What I Want
I’m thinking about how to revamp this website, and also rethink my presence of Facebook, Twitter, Flickr. I’m not quite sure what I want, but some of the problems I’ve noticed:
- These days, I often share links and things on Facebook, because that’s where most of my friends are, but then they are locked up on Facebook, which makes them hard to go back to even a few weeks later, and its only going to be worse when I move on from Facebook. Also, any comments/discussion things I post provoke end up trapped in Facebook.
- If I post things elsewhere, like Twitter, Flickr, or even directly on this blog, people I know often don’t find out about them.
- I think I want to create a division between my personal and professional presence on the web.
- I think I want to create some single-subject blogs, but still have them discoverable on Geekfun.
Just as I’m not entirely clear on the problem, I’m not entirely clear on the solution, but again, I have some ideas.
- Whenever practical, my interaction should be with a single self-hosted software package so that I have control and flexibility. At this point, I’m assuming that I would be using WordPress, plus some plugins to automatically push updates to Flickr, Facebook & Twitter.
- When it isn’t practical to publish through a self-hosted tool, updates, photos, etc posted to other sites/services, like Facebook, should also appear my own site as if it was published there directly.
- Updates, photos, etc distributed to other services should link back to the original, canonical copy of the update.
- Some easy way of routing updates
Pieces of the puzzle:
- WordPress on this and other blogs.
- Foursquare, Gowilla, or some other location-oriented service.
- Posts on other sites via BackType and Diqus.
- Photos uploaded to Flickr
- Status updates, links, photos, etc that I share on Facebook.
Amazon.com and AWS Down For Me, UltraDNS to Blame?
We noticed a bit ago that photos we had stored on Amazon S3 weren’t showing up. A little digging quickly revealed that things were timing out on DNS resolution for s3.
Looks like they are using UltraDNS as their DNS provider, and UltraDNS looks like it is offline too, at least from here.
Attack, or just really bad luck?
EAS:~ Erik$ dig +trace ultradns.net; <<>> DiG 9.6.0-APPLE-P2 <<>> +trace ultradns.net;; global options: +cmd. 15888 IN NS D.ROOT-SERVERS.NET.. 15888 IN NS L.ROOT-SERVERS.NET.. 15888 IN NS G.ROOT-SERVERS.NET.. 15888 IN NS E.ROOT-SERVERS.NET.. 15888 IN NS I.ROOT-SERVERS.NET.. 15888 IN NS M.ROOT-SERVERS.NET.. 15888 IN NS B.ROOT-SERVERS.NET.. 15888 IN NS H.ROOT-SERVERS.NET.. 15888 IN NS C.ROOT-SERVERS.NET.. 15888 IN NS K.ROOT-SERVERS.NET.. 15888 IN NS F.ROOT-SERVERS.NET.. 15888 IN NS A.ROOT-SERVERS.NET.. 15888 IN NS J.ROOT-SERVERS.NET.;; Received 228 bytes from 10.210.5.254#53(10.210.5.254) in 45 msnet. 172800 IN NS D.GTLD-SERVERS.net.net. 172800 IN NS B.GTLD-SERVERS.net.net. 172800 IN NS M.GTLD-SERVERS.net.net. 172800 IN NS E.GTLD-SERVERS.net.net. 172800 IN NS H.GTLD-SERVERS.net.net. 172800 IN NS J.GTLD-SERVERS.net.net. 172800 IN NS F.GTLD-SERVERS.net.net. 172800 IN NS L.GTLD-SERVERS.net.net. 172800 IN NS I.GTLD-SERVERS.net.net. 172800 IN NS K.GTLD-SERVERS.net.net. 172800 IN NS C.GTLD-SERVERS.net.net. 172800 IN NS G.GTLD-SERVERS.net.net. 172800 IN NS A.GTLD-SERVERS.net.;; Received 499 bytes from 192.36.148.17#53(I.ROOT-SERVERS.NET) in 203 msultradns.net. 172800 IN NS pdns1.ultradns.net.ultradns.net. 172800 IN NS pdns2.ultradns.net.ultradns.net. 172800 IN NS pdns3.ultradns.org.ultradns.net. 172800 IN NS pdns4.ultradns.org.ultradns.net. 172800 IN NS pdns5.ultradns.info.ultradns.net. 172800 IN NS pdns6.ultradns.co.uk.;; Received 221 bytes from 192.48.79.30#53(J.GTLD-SERVERS.net) in 146 ms;; connection timed out; no servers could be reachedEAS:~ Erik$ dig +trace s3.amazonaws.com; <<>> DiG 9.6.0-APPLE-P2 <<>> +trace s3.amazonaws.com;; global options: +cmd. 15605 IN NS C.ROOT-SERVERS.NET.. 15605 IN NS F.ROOT-SERVERS.NET.. 15605 IN NS E.ROOT-SERVERS.NET.. 15605 IN NS I.ROOT-SERVERS.NET.. 15605 IN NS A.ROOT-SERVERS.NET.. 15605 IN NS H.ROOT-SERVERS.NET.. 15605 IN NS K.ROOT-SERVERS.NET.. 15605 IN NS J.ROOT-SERVERS.NET.. 15605 IN NS B.ROOT-SERVERS.NET.. 15605 IN NS D.ROOT-SERVERS.NET.. 15605 IN NS L.ROOT-SERVERS.NET.. 15605 IN NS G.ROOT-SERVERS.NET.. 15605 IN NS M.ROOT-SERVERS.NET.;; Received 228 bytes from 10.210.5.254#53(10.210.5.254) in 41 mscom. 172800 IN NS D.GTLD-SERVERS.NET.com. 172800 IN NS I.GTLD-SERVERS.NET.com. 172800 IN NS F.GTLD-SERVERS.NET.com. 172800 IN NS L.GTLD-SERVERS.NET.com. 172800 IN NS H.GTLD-SERVERS.NET.com. 172800 IN NS K.GTLD-SERVERS.NET.com. 172800 IN NS G.GTLD-SERVERS.NET.com. 172800 IN NS C.GTLD-SERVERS.NET.com. 172800 IN NS B.GTLD-SERVERS.NET.com. 172800 IN NS A.GTLD-SERVERS.NET.com. 172800 IN NS M.GTLD-SERVERS.NET.com. 172800 IN NS J.GTLD-SERVERS.NET.com. 172800 IN NS E.GTLD-SERVERS.NET.;; Received 506 bytes from 192.33.4.12#53(C.ROOT-SERVERS.NET) in 44 msamazonaws.com. 172800 IN NS pdns1.ultradns.net.amazonaws.com. 172800 IN NS pdns2.ultradns.net.amazonaws.com. 172800 IN NS pdns3.ultradns.org.amazonaws.com. 172800 IN NS pdns4.ultradns.org.amazonaws.com. 172800 IN NS pdns5.ultradns.info.amazonaws.com. 172800 IN NS pdns6.ultradns.co.uk.;; Received 237 bytes from 192.43.172.30#53(I.GTLD-SERVERS.NET) in 220 ms;; connection timed out; no servers could be rea